Unconsolidated Affiliates Financial Data(Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014
Investment in unconsolidated affiliates	$ 4,501			$ 4,521
Equity in earnings of unconsolidated affiliates, net	52		91
CERC's ownership interest in Enable partners' capital	4,848			4,869
CERC's basis difference attributable to goodwill (1)	(217)	[1]		(217)	[1]
Equity Method Investment_Basis Difference To Be Accreted	(131)	[2]		(132)	[2]
CERC's total basis difference	(348)			(349)
CERC's investment in Enable	4,500			4,520
Proceeds from Equity Method Investment, Dividends or Distributions	72		70
Enable Midstream Partners [Member]
Investment in unconsolidated affiliates	4,500			4,520
Equity in earnings of unconsolidated affiliates, net	52		88
Operating revenues	616		1,002
Cost of sales, excluding depreciation and amortization	292		633
Operating income	104		162
Net income attributable to Enable	91		149
CERC's approximate interest	51		87
Basis difference accretion	1		1
CERC's equity in earnings, net	52		88
Current assets	407			438
Non-current assets	11,561			11,399
Current liabilities	841			671
Non-current liabilities	2,340			2,343
Non-controlling interest	31			31
Enable partners' capital	8,756			8,792
Proceeds from Equity Method Investment, Dividends or Distributions	72		67
Southeast Supply Header LLC [Member]
Investment in unconsolidated affiliates	1			1
Equity in earnings of unconsolidated affiliates, net	0		3
Proceeds from Equity Method Investment, Dividends or Distributions	$ 0		$ 3

[1] The difference relates to CERC’s proportionate share of Enable’s goodwill arising from its acquisition of Enogex LLC, and therefore will be recognized by CERC upon dilution or disposition of its interest in Enable.

[2] The difference will be recognized by CERC over 30 years beginning May 1, 2013. CERC will also adjust the accretable basis difference for dilution or disposition of its interest in Enable.